Hereditary cancer occurs because of an inherited genetic change called a mutation. Everyone has some genetic mutations, but some mutations are particularly common among people who share the same ethnicity. Individuals of Ashkenazi Jewish descent are 10 times more likely than the general population to have a BRCA mutation, which increases the risk of breast cancer in both women and men, ovarian cancer, prostate cancer, pancreatic cancer and melanoma. Overall, 1 in 40 Ashkenazi Jews carries a BRCA mutation.
Learn more about BRCA mutations.
Understanding Differences in Acquired and Inherited Cancer Mutations
All cancer is genetic, but only some cancer is hereditary. Cancer occurs when the normal mechanisms that control cell growth fail as a result of a genetic mutation. Without control, healthy cells can grow too rapidly or fail to correct changes, leading to cancer. A person can inherit a mutation from a parent and have it for life, or one can acquire a mutation during one’s lifetime.
For most people who develop cancer, the cancer-causing gene mutations result from acquired changes that happen over the course of a lifetime. Acquired mutations commonly arise in the natural process of aging and can also result from environmental factors such as UV exposure, radiation, chemicals, or viral infection. These mutations happen randomly and are not passed down from parents to children. Cancer caused by acquired mutations are called sporadic cancer. Most cancer cases -- about 90% -- are sporadic, and therefore not caused by inherited mutations.
Hereditary cancers result when individuals are born with an inherited genetic mutation that predisposes them to an increased risk for cancer. These individuals can also pass down these inherited genetic mutations to their children. Hereditary cancers account for about 10% of all cancers.
Cancers in people with hereditary risk tend to develop at younger ages compared to cancers in the general population. However, it’s important to note that a person who inherits a genetic change associated with increased cancer risk will not necessarily develop cancer.
What is My Risk for Hereditary Cancer?
It is impossible to tell from family history alone whether or not you are at risk for hereditary cancer. However, there are certain disease characteristics and patterns observed more frequently in hereditary cancers. The presence of the following features in a family may lead an individual to seek genetic counseling and, if appropriate, genetic testing:
- Two or more closely related individuals with breast cancer, diagnosed at any age
- Cancer diagnosed at young ages (before 50)
- Multiple cancer diagnoses in one individual (e.g. breast and ovarian, bilateral breast cancer)
- Individuals affected in multiple generations (e.g. grandfather, mother and aunt)
- Rare cancers such as ovarian cancer or male breast cancer
- Two or more family members with the same type of cancer (i.e. breast, ovarian, prostate, uterine, colon or stomach cancers)
- Ashkenazi Jewish ancestry
If one or more features listed above fits your family history, you could be at increased risk for a hereditary cancer. Genetic counseling services can help you further
assess your risk, decide whether or not genetic testing is appropriate, and talk through options for reducing risk.
Not sure where to go? The Norton & Elaine Sarnoff Center for Jewish Genetics can help you get started.